641540095621 has 2 divisors, whose sum is σ = 641540095622. Its totient is φ = 641540095620.

The previous prime is 641540095613. The next prime is 641540095631. The reversal of 641540095621 is 126590045146.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 350387044225 + 291153051396 = 591935^2 + 539586^2 .

It is a cyclic number.

It is not a de Polignac number, because 641540095621 - 2³ = 641540095613 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (641540095631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320770047810 + 320770047811.

It is an arithmetic number, because the mean of its divisors is an integer number (320770047811).

Almost surely, 2^641540095621 is an apocalyptic number.

It is an amenable number.

641540095621 is a deficient number, since it is larger than the sum of its proper divisors (1).

641540095621 is an equidigital number, since it uses as much as digits as its factorization.

641540095621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 259200, while the sum is 43.

The spelling of 641540095621 in words is "six hundred forty-one billion, five hundred forty million, ninety-five thousand, six hundred twenty-one".